|
|
You might have
caught wind over the past few years of some alarming
claims about the detriments of soy. This is terribly
confusing to those who consider it a health food. As
with most controversies the grey areas are huge. Even
as a health professional I am faced with mounds of
conflicting and inconclusive or weak research. Short
of devoting a life to the issue, this is what I have to
share thus far.
On the one hand, you
might have heard that soy contains high amounts of
proteins (including all essential amino acids) and is
rich in calcium, iron, zinc, phosphorus, magnesium, B
vitamins, omega-3 fatty acids and fiber. You may have
also heard that soy contains toxins, inhibits mineral
absorption, has poorly digestible proteins, or even that
it contributes to certain types of cancers. These
statements should be qualified and put into context.
Firstly, all foods contain substances that if eaten in
high enough quantities, or isolated and fed to rats in
high doses, are harmful. This includes grapefruit,
broccoli, lentils and celery. Secondly, many claims
made about soy, both good and bad, are based on
laboratory results exposing rats to high doses of
isolated compounds of soy. These don’t necessarily
translate to human experience. And lastly, but most
importantly, the form of soy is an extremely important
consideration.
Let’s
focus on the last point since I think that it is most
pressing and applies to so many issues around food
today. Soy has a long, unblemished and solid history in
Asian food culture. The first soy foods in Asia were
fermented products like tempeh, natto, miso and shoyu
(soy or tamari sauce). At a later date tofu and bean
curd became popular.
Large scale
cultivation of the soybean in the United States (mainly
for animal feed and soy oil) has prompted this industry
to find markets for the by-products of soy oil
manufacture in a society resistant to tasteless tofu and
unfamiliar tastes of fermented soy. Hence the
proliferation of soy products resembling traditional
American foods -soy milk, soy baby formula, soy yogurt,
soy dogs, soy ice cream, soy cheese, soy flour and
textured soy protein as meat substitutes. It is the
promotion of these as “health foods” that I strongly
disagree with. Not only do they hardly resemble soy in
Asian diets, but they are so prolific that many of us,
particularly vegetarians, consume far too much. Not
only may these “soy-look alikes” be unhealthy, but many
of the products (for example, soy burgers) are full of
sugar, additives and other unhealthy ingredients.
Here is some advice
regarding what to buy. Only buy organic non-genetically
modified soy. The GMO soy contains higher amounts of
many of the constituents considered to be problematic.
Non-organic soy contains very large amounts of
pesticides and herbicides. Eat mostly fermented soy
products like tempeh and miso; proper aging of soy
deactivates most problematic components. Good companies
will age miso up to 3 years. Never buy miso unless it
is refrigerated because the other varieties have been
pasteurized, killing off its natural good bacteria.
Enjoy moderate amounts of whole soy beans (Edamame).
Consume soy milk made with whole organic non-GMO soy
beans and water. Many varieties contain soy
by-products, sugar, preservatives and the like. Use
this soy milk as an occasional beverage. Avoid foods
made with soy proteins, soy protein isolate, texturized
soy protein, and/or soy oil. If you start reading
ingredients, you will be shocked to find they are
everywhere! Avoid soy-isoflavone supplements unless
advised by an alternative practitioner, as they may have
risks. Regard substitute meat and cheese products as
treats not staples. Avoid or limit soy products if you
have an under-active thyroid, are an infant, or have a
strong family history of breast cancer. If you have
digestive problems and/or allergies, soy could be the
culprit. Definitely think twice before using soy based
infant formulas. Enjoy healthy soy products but not at
the expense of other legumes (beans, peas, lentils,
etc.). Don’t consume soy protein powder unless under
advisement by a practitioner. Only buy the expensive
soy sauce (Tamari) that comes in glass bottle and says
“traditionally brewed”.
As for the cancer
issue, many of the studies are epidemiological
(population correlations), animal, or in vitro (that is,
done outside the body). The studies are conflicting and
are based on many different types of soy and doses.
This makes it impossible to generalize. If unsure about
a specific type of cancer please consult a health
professional.
The issue of using
soy for its phytoestrogen effect for the treatment of
menopausal hot flashes is no less controversial.
Studies show that sometimes soy phytoestrogens act as an
agonist (like estrogens) and sometimes like an
antagonist (against estrogen). If you have irregular
menstrual cycles and/or hot flashes, only use soy
therapeutically under advisement. This goes for cancers
as well.
If wanting to do you
own research search under the names John Robbins, Sally
Fallon and/or Weston A. Price Foundation. |